Internal combustion engine



June 1%, 1936. R. K. LEE

INTERNAL COMBUSTION ENGINE 2 Sheets-Sheet 1 Original Filed Feb. 16, 1933INVENTOR. Foyer Klee,

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TORNEYS,

M1318 16, R K E INTERNAL COMBUSTION ENGINE Original Filed Feb. 16, 19552 Sheets-Sheet 2 INVENTOR Page)" /I. Lea,

Patented June 16, 1936 INTERNAL CGMBUSTEON ENGINE Roger K. Lee, HighlandPark, Mich, assignor to Chrysler Corporation, Detroit, Mich, acorporation of Delaware 20 Claims. (Cl. 74-580) This invention relatesto internal combustion engines and refers more particularly toimprovements in means for transmitting power from the engine piston orpistons to the crankshaft, and

to improved mechanisms associated therewith.

This application is a division of my co-pending application, Serial No.657,146, filed February 16, 1933.

.t is an object of my invention to provide an improved connecting rodstructure and an improved assembly of connecting rods and crank pin orother operated device whereby the engine may be successfully operated atspeeds materially higher than the usual speeds of conventional enginesused for driving motor vehicles, for example. While my improvements arenot necessarily limited in their application to such high speed enginesor to engines for driving motor vehicles, they are particularly adaptedto such applications.

A further object of my invention is to provide an improved connectingrod of unusually light weight, at the same time affording the strengthrequisite for engine operation especially atrelatively high speeds.

Another object of my invention is to provide an improved connecting rodassembly particularly adapted to engines having radially arrangedcylinders wherein the connecting rod bearings may be relatively smalland compactly arranged in association with each other and with the crankpin operated thereby.

The desired increase in engine speeds over conventional practice is,among other things, limited by the loads produced by the weight of thereciprocating parts experienced at the connecting rod bearings, suchloads greatly increasing in magnitude as the piston speed increases anda further object of my invention is to overcome the aforesaiddifiiculties limiting engine operation at relatively high speeds.

Another object of my invention, in its somewhat more limited aspects, isto provide an improved connecting rod or rod assembly acting on acantilever crank or crank pin, the crank pin preferably being mountedfor rotation on its axis relative to the crankshaft rotation as thecrank pin is rotatably displaced by the connecting rods to e rotate thecrankshaft. Such arrangement permits the connecting rods to be made ofunusually light weight and to thereby minimize the forces produced bythe reciprocation of the connecting rods.

Still further objects of my invention are to provide an improvedconnecting rod structure wherein the rod is formed with a solid orunitary bearing; to provide an improved rod having a piston pin carriedas a unitary structural part of the main rod portion; and to provide atwo-piece connecting rod having component parts thereof securelyconnected to form a unitary structure comprising a bearing portion and amain rod portion.

Another object of my invention is to provide a unitary piston pin andconnecting rod structure and to provide a circular unitary connectingrod bearing portion free from customary caps and cap-securing bolts, thebearing portion being preferably attached by welding for added lightnessof weight to the main rod portion of the connecting rod structure.

An additional object of my invention is to provide an improvedconnecting rod assembly including a driving pin or equivalent elementfor actuating a mechanism associated with the engine such as the valvemechanism by way of example.

Further objects and advantages of my invention will be more apparentfrom the following detailed description of one illustrative embodimentthereof, reference being had to the accompanying drawings in which:

Fig. 1 is a sectional elevational view longitudinally through my engine,the section being taken along the line I-l of Fig. 2.

Fig. 2 is a transverse sectional elevational view through the valveoperating chamber of the engine shown in Fig. 1, parts of several of theengine cylinders being broken away.

Fig. 3 is a detail sectional View illustrating my connecting rod andcrank pin assembly, the section being taken along the line 33 of Fig. 1.

Fig. 4 is a further detail sectional view of the assembly shown in Fig.3, the section being taken along the line i4 of Fig. 3.

Figs. 5 and 6 are further detail sectional views of the assembly shownin Figs. 3 and 4, these views being respectively taken along the lines5-5 and E5-6 of Fig. 4.

Referring to the drawings, I have illustrated my improvements in aninternal combustion engine of the type having a plurality of cylindersl0 radially arranged with respect to the engine 'crankshaft H which isrotatably journaled by longitudinally spaced front and rear bearings l2and I3 respectively. The crankshaft H may be appropriatelycounterweighted, one counterweight thereof being illustrated at M at theforward portion of the crankshaft which projects beyond bearing l2 andinto the substantially cylindrical crankcase structure IS, the latterbeing provided with circumferentially spaced openings l6 concentric withand adapted to receive the respective cylinders I0. The rear portion ofthe crankshaft I projects through the crankcase extension cover I lwhich supports the aforesaid rear bearing l3 to provide a power take-offIQ for driving the motor vehicle or for operating such other machine ordevice as may be desired.

The crankshaft H is provided with a crank or crank pin l9 which,according to the present illustrated embodiment of my invention, isjournaled for rotation about its axis relative to the crankshaft duringrotary displacement of the crank pin by reason of the forward and rearantifriction type bearings 26 and 2| respectively. The crank pin I9 ispreferably of the cantilever type having a cantilever portion thereof 22which projects forwardly of the crankshaft l and into the crankcase l5for operation by the connecting rods 23, 24, and 25, these rodsextending radially outwardly from the crank pin for connection to therespective pistons 26 operating in the aforesaid cylinders H1.

Each cylinder I0 is provided with a suitable cylinder head 21 forming acombustion chamber 28, Fig. 1 illustrating a typical arrangement of acylinder and associated parts wherein the cylinder head 21 is ported forpassage of intake and exhaust gases under control of the intake andexhaust valves 29 and 30 respectively.

I have illustrated these valves as having a positive operation duringthe opening and closing movements thereof, the valve 30 being operatedby a lever arm 3| and the valve 29 being operated by a generally similarlever arm 32, these lever arms operating in the respective exhaust andintake gas passages 33 and 34 provided by the cylinder head cover member35. As illustrated in Fig. 2 the lever arm 32 is actuated by connectionwith a tubular rock shaft 36 journaled between the cover 35 and thecylinder head 21, the rock shaft 36 extending forwardly beyond thecylinder head 21 as shown in Fig. 1 for connection with the inwardlyextending lever arm 31. Likewise the lever arm 3| of the exhaust valve30 is connected with a rock shaft 38 telescoped within the rock shaft 36and extending forwardly therebeyond as illustrated in Fig. 1 forconnection with a similar operating lever 33. The operating lever arms31 and 39 extend inwardly into a valve operating chamber 43 which formsa forward extension of the crankcase l5 and is preferably substantiallyseparated therefrom by a transverse web or wall 4|. The circumferentialbounding wall of the chamber 40 is provided with circumferentiallyspaced openings 42 through which the respective pairs of lever arms 31and 39 extend for operating the respective valves 29 and 30 for eachcylinder. Journalled between the transverse wall 4| and a front coverplate 43 for the chamber 43 are a plurality of valve shafts 44preferably the same in number as the number of engine cylinders, eachvalve shaft having fixed thereto two pairs of cams 45. The arrangementis such that a pair of cams 45 on each valve shaft 44 cooperates with acorresponding pair of cams on the next adjacent valve shaft forreceiving therebetween the inner end of a pair of the lever arms 3'! and39 for positively reciprocating the intake and exhaust valves 23 and 30associated with each of the cylinders l6.

Each valve shaft 44 has a gear 46 located in the crankcase |5 fordriving the valve shaft associated therewith, the gears 46 meshing witha common driving pinion 41, the gears being so proportioned that for afour-stroke cycle engine the valve shafts 44 will be simultaneouslydriven in the same direction at half the crankshaft speed as willpresently be more apparent. In order to accommodate the various pairs oflever arms 37 and 39 in association with the operating cams 45, thepairs of cams on the respective valve shafts 44 or on certain of thesevalve shafts may be sufficiently spaced to prevent any interference atthe inner ends of the lever arms 31 and 39, it being understood thatcertain of the telescoping rock shafts 36 and 38 may project forwardlysufficiently to register the cam-operated lever arms assocated therewthwith the forwardly spaced pair of cams 45 shown in Fig. 1.

The aforesaid driving pinion 4'! has a driving disc 48, the pinion anddisc being journaled on a shaft 49 supported by the partition wall 4|and projecting rearwardly therefrom into the crankcase l5 adjacent theforwardly extending cantilever portion 22 of the crank-pin I9.

The valve gear driving disc 48 is provided with a circumferential seriesof openings 53 adapted to selectively receive the forwardly projectingend 5| of a driving pin 52 threaded at 53 into the forward end of thecrank pin l9.

The driving pin 52 is locked in place with the crank pin l9 as will bepresently more apparent, the end 5| being selectively engageable withthe openings of disc 48 in order to vary the timing of the valve drivingmechanism with respect to the crankshaft II. The openings 5|) arepreferably radially enlarged as shown in Fig. 1 so that the disc 48 willnot take any of the load of the crank pin IS, the disc 48 having onlyrotation with the crankshaft by reason of the projecting driving portion5| of the pin 52. Thus, the shaft 49 has its axis coinciding with theaxis of the crankshaft.

The pistons 26, cylinders 10, cylinder heads, valves, and valveoperating mechanism do not in themselves constitute a part of myinvention as claimed in this application, such parts being de scribedand claimed in my aforesaid co-pending application and other divisionsthereof and I desire to point out that such parts may be of any desiredconstruction and arrangement within keeping of the general objects andspirit of my invention.

Each of the aforesaid connecting rods such as the connecting rod 23illustrated in Fig. l is formed of a main rod or column portion 54preferably in the form of a hollow cylindrical tube for lightness ofweight and maximum strength. The outer end of each main rod portion 54receives the hollow stem 55 of a hollow piston pin 56, the stem 55 beingpreferably welded in place to the main rod portion 54 to providesubstantially a unitary T-shaped outer end for each of the connectingrods.

Each piston pin 56 may be suitably connected with an associated piston26, the construction illustrated including a pair of piston pin bosses5'! adapted for assembly on the piston pin and then inserted intosuitable openings in the head of the piston and secured thereto in anappropriate manner which may include welding as indicated at 58.

The inner end of the main rod portion 54 of the connecting rod 23receives the outwardly extending stem or projection 59 which ispreferably hollow to further lighten the weight of the connecting rod,the stem being secured in place pref erably by welding.

The stem 59 has a solid or unitary annular bearing portion 60 adapted toreceive the cantilever portion 22 of the crank pin IS. The annularbearing has a forward opening 6| fitting the crank pin portion 22 and asecond opening 62 which may be stepped as shown in Figs. 1 and 4 to fita correspondingly stepped peripheral space of a flange 53 projectingoutwardly from the crank pin l9, this stepped engagement holding theannular bearing 66 in position against rearward axial movement along thecrank pin 29 and also providing a rear bearing face between the crankpin and the annular bearing 60. The hearing portion 60 is provided withan outer circumferential flange 54 which serves to stiffen the bearingportion and to prevent distortion or" the axially spaced engagedbearings and 62.

Intermediate these spaced bearing openings 6i and 62, the bearingportion has a cylindrical opening adapted to receive therewithin theannular bearings 66 and 61 of the remaining connecting rods 25 and 20respectively, these annular bearings having outwardly extending stems 59connected to the respective main rod portions of the connecting rods ina manner similar to that heretofore described in connection with thestem 58 of the connecting rod 23.

The annular bearings 66 and 61 are preferably likewise of solid orunitary construction, these annular bearings being journaled forrelative rotation on the cantilever portion 22 of the crank pin [9. Itwill furthermore be noted that these annular bearings 65 and 61 haveside faces in contact with each other, the bearing 60 contacting withthe bearing 65 and the bearing 5'! contacting with the shoulder portionof the crank pin [9 adjacent the aforesaid flange 63.

The bearing 60 of connecting rod 23 is provided with a pair ofcircumferentially and axially spaced slots or openings 68 and 69 throughwhich the stem portions 69' of the respective bearings 6'! and 66project, the slots being of sufllcient arcuate length to permit theangular swinging movement of the connecting rods 24 and 23 during theiroperation. The cylinders l0 preferably have their axes coplanar, thestem portions 59 being thus slightly offset axially of the crank pinwith respect to their associated bearings 65 and 6'! as illustrated inconnection with the connecting rod 24 illustrated in Fig. 4.

The aforesaid valve gear driving pin 52 is provided with an outwardlyextending annular flange 10 best illustrated in Figs. 4 and 6, thisflange acting against the forward side face of the bearing 60 andthereby cooperating with the rear stepped bearing opening 62 to maintainthe connecting rods in assembly on the cantilever end 22 of the crankpin l9. In order to secure the driving pin 52 with the crank pin and thelatter with the connecting rod 23, the flange l0 and bearing 60 areprovided with cooperating annular grooves receiving aninwardly-springing lock ring 1!, this ring having one of its ends bentinwardly at 12 to engage aligned openings 13 and 14 respectivelyprovided in the contacting faces of bearing 68 and crank pin I9 with thedriving pin 52. Thus, the connecting rod 23 has its bearing 60 fixed tothe cantilever portion 22 of the crank pin 19, the connecting rods 24and 25 having their respective bearings 61 and B5 articulated on thecantilever portion of the crank pin. Furthermore, it will be noted thatthe bearing 60 spans the annular bearings 66 and 6'! so as to axiallyoverlap these bearings and receive these bearings within the opening 65of the bearing 60.

It will be noted that each'of the bearing openings 6| and 62 of thebearing 60 present less bearing area in a direction transversely ofcrank pin l9 than either of the corresponding bearing areas presented.by the bearings 66 and 61, the arrangement being preferably such thatthetotal bearing areas of the bearings .60, 66, and 61 on the crank pinI9 are substantially the same.

As the pistons 26 successively operate inwardly through their respectiveconnecting rods, the crank pin i9 will rotate the crankshaft ll, thedriving pin 52 operating the valve shafts G4 in unison to positivelyoperate the intake and exhaust valves 29 and 30 associated with eachcylinder I0 in properly timed sequence of operation. The crank pin I9being connected with the connecting rod 23 will therefore have rotationon its axis relative to the rotation of the crankshaft l l by reason ofthe bearings 20 and 2| carried by the crankshaft.

My improvements are adapted to permit relatively high engine speeds suchas 5,000 to 10,000 R. P. M. although it will be understood that suchvalues of engine R. P. M. are cited herein only for illustrativepurposes in order to illustrate the unusual operating characteristics ofmy improvements and such values in practice may be varied as desired.

Various modifications and changes will be readily apparent from theteachings of my invention, as set forth in the appended claims, and itis not my intention to limit my invention to the particular details ofconstruction and operation shown and described for illustrativepurposes.

What I claim is z.

i. In an internal combustion engine having a crank, a plurality ofconnecting rods radiating from said crank, each of said connecting rodshaving an annular cylindrical bearing operatively engaging said crank,the cylindrical bearing of one of said connecting rods being positionedwithin the cylindrical bearing of another of said connecting rods.

2. In an internal combustion engine having a crank, a. plurality ofconnecting rods radiating from said crank, each of said connecting rodshaving an annular cylindrical bearing portion provided with a bearingsurface operatively engaging with said crank, one of said cylindricalbearing portions being overlapped with another cylindrical bearingportion longitudinally of said crank.

3. In an internal combustion engine having a crank, a plurality ofconnecting rods radiating from said crank, each of said connecting rodshaving an annular cylindrical bearing portion provided with a bearingsurface operatively engaging said crank, one of said cylindrical bearingportions being overlapped with another cylindrical bearing portionlongitudinally of said crank, said overlapping annular bearing having anopening intermediate the length of its cylindrical portion receiving theconnecting rod of the overlapped cylindrical bearing portion.

4. In an internal combustion engine having a crank, a plurality ofconnecting rods radiating from said crank, each of said connecting rodshaving an annular cylindrical bearing portion surrounding said crank andprovided with a bearing surface operatively engaging said crank, one ofsaid cylindrical bearing portions spanning another longitudinally ofsaid crank.

5. In an internal combustion engine having a crank, a plurality ofconnecting rods radiating from said crank, each of said connecting rodshaving an annular cylindrical bearing portion surrounding said crank andprovided with a hearing surface operatively engaging said crank, one ofsaid cylindrical bearing portions receiving a plurality of other of saidcylindrical bearing portions therewithin.

6. In an internal combustion engine having a crank, a plurality ofconnecting rods radiating from said crank, each of said connecting rodshaving an annular cylindrical bearing portion surrounding said crank andprovided with a bearing surface operatively engaging said crank, one ofsaid cylindrical bearing portions overlapping a plurality of other ofsaid cylindrical bearing portions longitudinally of said crank.

7. In an internal combustion engine having a crank, a plurality ofconnecting rods radiating from said crank, each of said connecting rodshaving an annular cylindrical bearing portion surrounding said crank andprovided with a hearing surface operatively engaging said crank, one ofsaid cylindrical bearing portions spanning a plurality of other of saidcylindrical bearing portions longitudinally of saidcrank.

8. In an internal combustion engine having a crank, a plurality ofconnecting rods radiating from said crank, each of said connecting rodshaving an annular cylindrical bearing portion surrounding said crank andprovided with a bearing surface operatively engaging said crank, one ofsaid cylindrical bearing portions having axially spaced bearing surfaceportions thereof engaging said crank, another of said cylindricalbearing portions having its bearing surface engaging said crankintermediate said spaced bearing surface portions.

9. In an internal combustion engine having a crank shaft provided with acrank pin rotatably journalled therein, a plurality of connecting rodsradiating from said crank pin, annular bearings respectively carried bysaid connecting rods and arranged adjacent one another axially of saidcrank pin, said bearings rotatably engaging said crank pin.

10. In an internal combustion engine having a crank pin, a plurality ofconnecting rods radiating from said crank pin, annular cylindricalbearings respectively carried. by said connecting rods said bearingshaving bearing surfaces arranged adjacent one another axially of saidcrank pin, one of said cylindrical bearings spanning a plurality ofothers axially of said crank pin and being non-rotatably connected tosaid crank pin, said other cylindrical bearings rotatably engaging saidcrank pin within said span.

11. In an internal combustion engine having a cantilever crank pin and avalving mechanism driven therefrom, a plurality of connecting rodsradiating from said crank pin, each of said rods having a bearingsurrounding said pin, and means carried by said pin for maintaining saidhearings in position and for imparting a drive from said pin to saidvalving mechanism.

12. In a unitary connecting rod structure, a T- shaped portion providinga piston pin at one end thereof, said T-shaped portion having aninwardiy extending stem, a unitary bearing portion at the other endthereof, the outer end of said main rod portion being secured to saidstem, a hollow main rod portion intermediate said piston pin and bearingportions, said bearing portion having a crank pin receiving opening andan outwardly extending stem adjacent thereto, the inner end of said mainrod portion being secured to said outwardly extending stem.

13. In an internal combustion engine having a cantilever crank pin and avalving mechanism driven therefrom, a plurality of connecting rodsradiating from said crank pin, each of said rods having a bearingsurrounding said pin, and means carried by said pin for maintaining saidbearings in position and for imparting a drive from said pin to saidvalving mechanism, said means comprising a drive pin projecting beyondthe crank pin in the direction of the axis thereof.

14. In an internal combustion engine having a cantilever crank pin and avalving mechanism driven therefrom, a plurality of connecting rodsradiating from said crank pin, each of said rods having a bearingsurrounding said pin, and means carried by said pin for maintaining saidbearings in position and for imparting a drive from said pin to saidvalving mechanism, said means comprising a drive pin projecting beyondthe crank pin in the direction of the axis thereof, said drive pinhaving a flange extending therefrom transversely to the axis of saiddrive pin and radially outwardly therefrom beyond said crank pin toprovide an abutment for said bearings.

15. In an internal combustion engine having a cantilever crank pin and avalving mechanism driven therefrom, a plurality of connecting rodsradiating from said crank pin, each of said rods having a bearingsurrounding said pin, and means carried by said pin for maintaining saidbearings in position and forimparting a drive from said pin to saidvalving mechanism, said means comprising a drive pin having a portionthereof seated within the end of said crank pin.

16. In an internal combustion engine having a cantilever crank pin and avalving mechanism driven therefrom, a plurality of connecting rodsradiating from said crank pin, each of said rods having a bearingsurrounding said pin, and means carried by said pin for maintaining saidbearings in position and for imparting a drive from said pin to saidvalving mechanism, said means comprising a drive pin having a portionthereof seated within the end of said crank pin, said drive pin having aradially extending flange engaging the end of said crank pin and one ofsaid bearings.

1'7. In an internal combustion engine, a rotatable crankshaft, a crankpin having its axis extending parallel to the crankshaft axis and beingradially offset therefrom, means rotatably journalling one end of saidcrank pin in said crankshaft for rotation relative to said crankshaftrotation, said crank pin having a cantilever portionextending from saidcrankshaft in the direction of said crank pin axis, and a plurality ofconnecting rods radiating from the cantilever portion of said crank 18.In an internal combustion engine, a rotatable crank shaft, a crank pinhaving its axis extending parallel to the crankshaft axis and beingradially offset therefrom, means rotatably journalling one end of saidcrank pin in said crankshaft for rotation relative to said crankshaftrotation, said crank pin having a cantilever portion extending from saidcrankshaft in the direction of said crank pin axis, a plurality ofconnecting rods having annular bearings arranged side by side along saidcantilever portion of said crank pin, and means for operably positioningsaid rods on said cantilever pin portion to prevent displacement thereofaxially of said crank pin.

19. In an internal combustion engine, a rotatable crankshaft, a crankpin having its axis extending parallel to the crankshaft axis and. beingradially offset therefrom, means rotatably journalling one end of saidcrank pin in said crankshaft for rotation relative to said crankshaftrotation, said crank pin having a cantilever portion extending from saidcrankshaft in the direction of said crank pin axis, a, plurality ofconnecting rods having annular bearings arranged side by side along saidcantilever portion of said crank pin, and an abutment carried by saidcrank pin substantially intermediate said journalled end portion andsaid cantilever portion for preventing displacement of said connectingrod bearings axially of said crank pin in a direction toward saidcrankshaft.

20. In an internal combustion engine, a 1'0- tatable crankshaft, a crankpin having its axis extending parallel to the crankshaft axis and beingradially offset therefrom, means rotatably journalling one end of saidcrank pin in said crankshaft for rotation relative to said crankshaftrotation, said crank pin having a cantilever portion extending from saidcrankshaft in the direction of said crank pin axis, a plurality ofconnecting rods having annular bearings arranged side by side along saidcantilever portion of said crank pin, an abutment carried by said crankpin substantially intermediate said journalled end portion and saidcantilever portion for preventing displacement of said connecting rodbearings axially of said crank pin in a direction toward saidcrankshaft, said crank pin having an axial bore open at the free end ofsaid cantilever portion, and a pin seated in said opening and having aradial flange providing an abutment for preventing displacement of saidconnecting rod bearings axially of said crank pin in a direction awayfrom said crankshaft.

ROGER K. LEE.

